Process and apparatus for the production of long continuous electric arcs.



o. SCHNHBRR C J.- HESSBERCER.

PROCESS AND APPAATCS E011 THE PRODUCTION or IICNC'CCNMNCCCS ELECTRIC ARCS.

APPLICATION FAILED 00T. 17, 1912.'.

Patents@ May 5, 1914.

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UNITED STATE vPATENT onirica.

OTTO SCHNHERR, OF DRSDEN-STRIESEN, GERMANY, "AND JOI-IANNES HESSLBERGER,

0F CHRISTIANSAND, NORWAY, ASSIGNORS T0 NORSK HYDRO-ELEKTRISK KVAEL- STOFAKTIESELSKAB, OF CHRISTIANIA, NORWAY', .A CORPORATION 0F NORWAY.

PROCESS AND APPARATUS FOR THE PRODUCTION- 0F LONG CONTINUOUSi ELEGTRI ARCS. A

'Patented May 5, 1914.

Original application filed May 18, 1910, Serial Nett-32,097. Divided and this application led October 17,

v 1912. Serial No. 726,368.

To all who/m, it may cantieri.-

Be it known that we, O'r'ro SCHN-mnu and Jol-nannies Hnssnnenn, subjects of the King of' Saxony and the King of Prussia, respectively, residing, respectively, at Dresden-Striesen, Germany, and Christiansand, Norway, have invented new'and useful Improvements in Processes andApparatus for the Production of Long Continuous Electric- Arcs, of which the followingis a specification.

The subject of this application was originally file d May 18th 1910,' Serial No. 562,097, the present specification and claims being'a division of the same pursuant to the requirement of the PatentOtlicc.v

In the specification of Letters Patent No. 930238 we have -described the production of long stable electric arcs byV causing an are. tospring from an insulated electrode connected with one pole of a source of electricity and situated at, or toward, one end of a long tube, or passage, the tube,`or passage, itself being either connected with the other pole of the source of electricity, or containing at, or toward, the other end thereof, a second electrode connected with the other pole of the source of electricity, while at thesame time a current of air, or other gas, or gases, is passed through the tube` or passage, with such velocity that a long and steadily burning electric are is produced and maintained Within the said tube, or passage. The said specification discloses, for the first. time, a new principle, namely surrounding a long electric are with a layer of non-conducting fluid and maintaining this layer of Huid in such a condition that it is easier for the are to continue in the position iu which it is burning than for it to spring through the layer of surrounding fluid. ln oriler to bring about this condition, it is necessary that the layer of gas, (which we will hereinafter, for brevity, refer to as air, although other gas, under which term we include a gaseous mixture, may be used in carrying out this invention)v` should not be allowed to become so hot that it is capable of conducting electricity, or at all events that it should not reach this high temperature until ital-rives at a point 1u the tube, or passage (which we will hereinafter, for brevity, re-

fer to as the tube), where it is` desired that the are should pass through the layer'to the second electrode or its equivalent. A partlcular method-of carrying out the principle set forth consists, as described in the aforesaid speciication, in passing a current of air in' one direction through the tube, in which the are is'produccd, commencing at a point either` below, orat a short distance above, the insulated electrode. It is also preferable, according tothe said specification, that the air should be passed into the tube with a tangential, or rotary, motion.

The' specification of Letters Patent No. 976,002 describes the production of stable provided with an insulated electrode and leading into a common space. Air is blown past each electrode into therespeetive tube and is led away from the common space, while the arcs produced may join qin the common space and form one continuous are.

In Figure 3 of the drawings accompanying the last-named specification the two tubes are'shown parallel to one another, but the specification does not restrict the -artwo tubes may be placed end on to one another so that one straight continuous are 1s air being blown past each electrode and being withdrawn from the. tube at, or near. the mid part thereof. We have discovered tube as described in the said specification, the arc lan also be produced and maintained 'with certain advantages if the air be made to pass through the tube. or through different portions ot' the tube in different directions lengthwise of -the tube at one and the same time as hereinafter explained. For insta-nce the air can be passed along the wall inside the tube in one direction and lnediatcly surrounding the arc, so thatit passes through the said tube or through different portions thereof, lside by side, in dif` ferent directionslengthwise of the said tube at om` `and the saine time, or the air can be .caused to pass in two opposite directions along diiferent portions of the arc, preferl ably being withdrawn through each elecelectric arcs by means of two tubes, eachv then back again iu the reverse direction iin-V rangement to this particular position, as the obtained between two insulated electrodes,

that instead of the air passing through the f trode, or through the parts of the apparatoward the mid part and then reverses its 4arc can be a long cylinder. This latter tus which act as electrodes, or these variations can be combined so that air is introduced into the tube at each of the two ends thereof and passes along the interior wall courseA so as to pass back along the arc toward each of the two ends ofthe tube again.

When carrying out this invention We prefer to impart to the air, or to part of the air, entering the tube a tangential, or rotatory, motion, for instance such as is described in the aforesaid speci'cation of Letters Patent No. 930,238, and it is also generally advisable to cool the openings through which the hot gases are removed from the tube. The tubes which can be used in carrying out this invention mayA be variously shaped, for instance the tube containing the shape is more particularly useful when the gases are taken away from each end of the tube.'

We prefer generally to surroundthe tube containing the electric arc with a second tube and to pass the air through the space between thetwo' tubes before allowing it to enter the inner tube, so that in thisway the temperature of the inner tube is lowered and the air becomes preheated before entering the inner tube and consequent-ly a higher temperature of the arc is admissible within the inner tube than would be the case if no such preheating took place. Vhen, according to this invention, the air passes along the interior wall of the tube and then back aga-in immediately surrounding the arc, a further advantage is attained", because heat is able to pass directly from the air immediately'surrounding the are to that which is moving in the opposite direction 'along the interior wall ot' the tube, and the transference of heat is greater because there is no intermediate wall through which the heat has to pass and since the hottest i air does nel come into contact with the wall i of the tube a much higher temperature of the arc can be employed within the tube! than would be the case if the temjjierature ,l of the arc has to be restricted to proventi the materialiol which the tube is made from being-injuredlVhen the air is led into the tube at one end only and the gases are j removed at the saine' end. the tube can be l cone-shaped the entrance and exit being at j the larger end of the cone. Tf desired, instead of introducing' the l l l whole supply` ofl air into the tube in the manner hereinbefore described, it can be intro'duecd partly in such manner land partly in any other suitable way, for instance as vdescribed in the specification of the atoresaid Letters Patent No. 930,238.

The electrodes employed in carrying out the 'process according to this invention cai be of various shapes. Foiwinstance they can be rod-shaped, as described in the aforesaid specification of, Letters Patent No.

930,238, or they can be formed like a ring,

andthe end of the arc can continually move around the ring. i

lVe give the following ways as examples of how this invention can be performed in practice, referring to the accompanying.,r drawings, but the invention is not limited to these examples.

In the drawings, each of the l*1 igs. l to 5 inclusive represents vertical sections ot' apparatus suitable for use according to this invention, showing how the electric arc canv be produced and how the gas is caused to pass in the desired direction or directions.

In the arrangement shown in Fig. 1, two tubes are employed, namely anupper one K of inverted funnelshape, partly entering a lower tube R so that there is a small ringshaped opening r between them and through this openlng the air is passed with-a suitablevelocity into the lower tube R, the said air passing down the interior of the wall thereof toward the electrode P which is situated at the lower end of the said tube R, and then takingv a course in the opposite direction, as indicated by the arrows, and passing away through the upper tube K. When an electric are is formed between the electrode P. and the upper tube K, or a special electrod'e situated in the said tube K (for instance by momentarily short circuiting these two parts), the arcl produced burns quietly in the lower tube R starting from the electrode P and ending either onthe upper tube K, or on the special electrode situated in the said tube-K. YVeprefer to introduce the air into the. lower tube R so that the `said air has a tangentiaL'or rotatory, motion, and for this purpose an apparatus such as that illust-rated in Fig. 2' can be employed. ln this ligure,l E is a metal ring situated in the upperpart of the lower tube R, the said ring E having tangential openings in it so that the air passes into the tube R'with a rotatory motion, and' for the greater part downward along the interior wall of the tube R towardthe electrode P, then takes an upwardv course nearer the axis of the tube R, and finally the gases pass awaythrough the upper tube K. As shown' in the figure, the said electrode l and the lower tube R may be electrically connected together and be insulated from the other parts of theapparatus. The electric are can be started by short-circuitingthe up er and lower. tubes R and K, the one en of the are being driven down by the air current and terminatinv' on the said electrode P, which is preferably cooled. for instance by means ofwater. As' shown in this ligure, the lower tube R can be mrsufficient .velocity to fellow the coursesI indirounded by a second tube and the air can be passed, through the* pi e e, upward between these two tubes be ore entering the inner tube R through the aforesaid tangentially perforated ring R. The other end of t-he arc can be situated on the upper tube K, either adjacent to the lower 'tube E, or at some distance above it. lf desired, a special yelectrode can be provided 'in the upper tube K, in which case the arc burns between this electrode and the elec- `trode P.. Instead of all the air passing through the aforesaid ring E down the lower tube, some of it may be passed up the upper .tube K Wit-hout entering the lower tube R, and the p-roportion of air which follows this couse Will depend upon the relative sizes of the said tubes K and R. This is the case with the arrangement Fig. 2. The portion of the air passing directly through the upper tube K mixes with the heated gases leaving the lower tube R and tends to cool them down quickly, and this is ofadvantage when the electric arcs are used for carrying out endotherniic reaction iri gases, for instance for the production of nitric oxid. Of course the gases can be further subjected to a cooling process by using special means for cooling the upper tube K, for instance it can be surrounded by a water jacket as indicated in Fig. 5 afterthe manner of a Liebigs condenser.v

Fig 3 illustrates the use of a cone-shaped lower tube R which is insulated from the rest of the apparatus, the air passing in through Vtheopening 1v between the tubes K and R into the lower tube, down the interior inclined wall thereof and then upward surrounding the axis. If desired, air can also be introduced at the lower end of the said lower tube R as illustrated by the arrow. When such an apparatus is used there is a tendency for the end oi the arcrto describe a circular path around the inner Wall ot the cone-shaped tube R.

Fig.l l illustrates an arrangement in which air is introduced at each of the two ends of the tube R, passing along the inner wall thereof, then reversing its course so as to pass back along the arc, the gases inally leaving the tube through the t-Wo insulated electrodes P, P. and passing out by the passages K, K1. The electrodes may, if desired, i

be cooledl hy means of Water-jackets. A ring T may, it desired, be situated, asv shown, in the tube R to assist in directing the course of the air which enters ai any convenient number ol openings (indicated at E E1) with two electrodes, or between .each electrode and the tube R. If desired, however, one of the electrodes may loe electrically connected to the tube R, while the other electrode vis insulated therefrom, in which case the arc can be started by short-circuiting this second electrode with the tube R. A

In all the figures L represents insulating material;

What we claim is:

l. In producing long stable electric arcs by forcing a current of gasalongside ofthe body of the discharge causing the gas to pass at different portions of the arc side by side in reverse directions lengthwise of the said arc at one and the same time.

2. In producing long stable electric arcs by forcing a current of gas alongside of the body of the discharge causing the gas to pass at diierent portions of the arc side by side in reverse directions lengthwise of the said arc at one and the same time and causing the gas to leave the discharge space at the end of the arc and centrally with reference to said arc the gais being subjected t0 the cooling on its passing out ofcontact with the arc.

3. An apparatus ot the kind described comprising a tube connected with a source of electricity, connections to lead to a blast generator and means for causing gas to enter at one end of the said tube to travel alongside of the\arc produced and reverse its course leaving the tube at or near the end at which the said gases entered.

4. An apparatus of the kind described lated from a second tube and connected with a source of electricity, connections to leadnto comprising a tube surrounded by and insu-` a blast generator and means for causing gas to enter the space between the two said tubes and then to pass from the said space intoone end of the said inner tube to travel along the tube and to reverse its course leaving at 01' near the end at which the said gas entered the said inner lube,

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses. n

OTTO SCHONHERR. JOHANNES I'IESSBERGER. lVitnesses to the signature of Otto Schnherr:

lM'l, Aunis. Au'rnun Gunn. Y Witnesses as to the signature ot Joh. 

